1. Field of the Invention
The present invention relates to an optical pickup, and more particularly, to an optical pickup using a two-wavelength light source module in which two light sources that emit different wavelengths of light are integrated into a single package, and a method of correcting an optical position difference between the different light beams.
2. Description of the Related Art
Generally, DVD-CD compatible optical pickups are configured to have two separate light sources for a DVD and a CD. The problem with this is that it makes the configuration of an optical system more complicated and is subject to restrictions on installation space due to the needs to compose optical lens to best suit the characteristics of the DVD and the CD, and to assemble the two light sources.
In recent years, a light source module called TWIN-LD has been developed. This module is formed by integrating two light sources, that is, two semiconductor laser chips (LDs), to emit different wavelengths of light for a DVD and a CD, into a single package. However, since this light source module suffers from a large position difference between the light sources, it can only be used in optical pickups for reproducing, and not for recording.